Diseased Tree Control
The City monitors the insect and disease problems of trees in the community and issues citations citywide for diseased and infectious trees.
If you suspect a problem with a tree on your property you may request an on-site inspection . The City Forester will help identify possible disease and will assist with recommendations for treatment or removal.
Many agencies and organizations within Minnesota provide such great resources on insect and diseases. Please refer to the quick links provided for more information.
Emerald Ash Borer (EAB)
With the discovery of Emerald Ash Borer (EAB) in Minnesota last year, people with ash trees on their property are concerned about possible attacks from EAB and what they should do, if anything, to protect their trees. EAB has been confirmed in Anoka County.
Report
If you think you have found emerald ash borer, visit University of Minnesota Extension for more information on how to determine if your trees are affected and resources for possible treatment options. Those without Internet access can call Forest Resources Extension at 612-624-3020.
Minnesota Department of Agriculture
Additional information on EAB is available through the Minnesota Department of Agriculture.
The City has provided copies of the Emerald Ash Borer information provided by the University of Minnesota Extension office and Minnesota Department of Agriculture.
Bur Oak Blight (BOB)
Symptoms
BOB occurs only on bur oaks. Leaf symptoms typically first appear in late July or August. Infected leaves develop brown lesions that are wedge-shaped and often delimited by leaf veins. It is also common for the leaf veins, themselves, to turn brown. Individual lesions may cause large areas of the leaf to turn brown, resulting in an overall wilted or scorched appearance to the leaves.
During the summer, black, pimple-like fruiting structures of the fungus form along the leaf veins and petioles and can be easily seen with the aid of a magnifying lens. Leaf symptoms are usually more severe on the bottom half of the affected tree’s crown, but over time, symptoms may spread throughout the crown
A unique feature of BOB is that some infected leaves will remain on the tree during the winter (healthy bur oak trees shed all of their leaves in the fall). It is important to note that some leaves, even a small number, are retained over the winter is an indication that BOB may be present.
Spread
BOB appears to be a slow spreading disease, particularly as it relates to disease spread from tree to tree. It remains a mystery as to why BOB does not spread more rapidly because the spores that cause BOB are produced in great abundance and are spread by rain. Within an individual tree, the disease tends to intensify year to year, generally starting in the bottom of the crown and moving upwards. If a tree is seriously affected one year, it tends to be severely affected the next year.